Multi-state memory

Abstract

Maximized multi-state compaction and more tolerance in memory state behavior is achieved through a flexible, self-consistent and self-adapting mode of detection, covering a wide dynamic range. For high density multi-state encoding, this approach borders on full analog treatment, dictating analog techniques including A to D type conversion to reconstruct and process the data. In accordance with the teachings of this invention, the memory array is read with high fidelity, not to provide actual final digital data, but rather to provide raw data accurately reflecting the analog storage state, which information is sent to a memory controller for analysis and detection of the actual final digital data.

What is claimed is:  
     
       1. A multi-state memory comprising: 
       a plurality of EEPROM memory cells, each for storing one of a plurality of multi-states, organized into a plurality of sectors;  
       one or more tracking cells for each of said multi-states, associated with each of said plurality of sectors;  
       read circuitry for reading raw data associated with the programmed state of said tracking cells;  
       converter circuitry for converting said raw data to digital form; and  
       a memory controller for establishing desired read points for each of a plurality of physical states, based upon said raw data converted to digital form read from each said tracking cell.  
     
     
       2. A multi-state memory comprising: 
       a plurality of EEPROM memory cells, each for storing one of a plurality of multi-states, organized into a plurality of sectors;  
       one or more tracking cells for each of said multi-states, associated with each of said plurality of sectors;  
       read circuitry for reading raw data associated with the programmed state of said tracking cells;  
       converter circuitry for converting said raw data to digital form; and  
       a memory controller for establishing desired read points for each of a plurality of physical states, based upon said raw data converted to digital form read from each said tracking cell.